public class FeatureClassDescription : TableDescription 

FieldDescription bigIntegerFieldDescription = new FieldDescription("BigInteger_64", FieldType.BigInteger);

// 64-bit
FieldDescription oidFieldDescription_64 = new FieldDescription("ObjectID_64", FieldType.OID)
{
  Length = 8
};

// 32-bit
FieldDescription oidFieldDescription_32 = new FieldDescription("ObjectID_32", FieldType.OID)
{
  Length = 4
};

// Earthquake occurrences date and time

// 9/28/2014 (DateOnly)
FieldDescription earthquakeDateOnlyFieldDescription = new FieldDescription("Earthquake_DateOnly", FieldType.DateOnly);

// 1:16:42 AM (TimeOnly)
FieldDescription earthquakeTimeOnlyFieldDescription = new FieldDescription("Earthquake_TimeOnly", FieldType.TimeOnly);

// 9/28/2014 1:16:42.000 AM -09:00 (Timestamp with Offset)
FieldDescription earthquakeTimestampOffsetFieldDescription = new FieldDescription("Earthquake_TimestampOffset_Local", FieldType.TimestampOffset);

// 9/28/2014 1:16:42 AM (DateTime)
FieldDescription earthquakeDateFieldDescription = new FieldDescription("Earthquake_Date", FieldType.Date);

public void CreateFeatureDatasetWithFeatureClassSnippet(Geodatabase geodatabase)
{
  // Creating a FeatureDataset named as 'Parcel_Information' and a FeatureClass with name 'Parcels' in one operation

  string featureDatasetName = "Parcel_Information";
  string featureClassName = "Parcels";

  SchemaBuilder schemaBuilder = new SchemaBuilder(geodatabase);

  // Create a FeatureDataset token
  FeatureDatasetDescription featureDatasetDescription = new FeatureDatasetDescription(featureDatasetName, SpatialReferences.WGS84);
  FeatureDatasetToken featureDatasetToken = schemaBuilder.Create(featureDatasetDescription);

  // Create a FeatureClass description
  FeatureClassDescription featureClassDescription = new FeatureClassDescription(featureClassName,
    new List<FieldDescription>()
    {
      new FieldDescription("Id", FieldType.Integer),
      new FieldDescription("Address", FieldType.String)
    },
    new ShapeDescription(GeometryType.Point, SpatialReferences.WGS84));

  // Create a FeatureClass inside a FeatureDataset
  FeatureClassToken featureClassToken = schemaBuilder.Create(new FeatureDatasetDescription(featureDatasetToken), featureClassDescription);

  // Build status
  bool buildStatus = schemaBuilder.Build();

  // Build errors
  if (!buildStatus)
  {
    IReadOnlyList<string> errors = schemaBuilder.ErrorMessages;
  }
}

public void CreateFeatureClassInsideFeatureDatasetSnippet(Geodatabase geodatabase)
{
  // Creating a FeatureClass named as 'Tax_Jurisdiction' in existing FeatureDataset with name 'Parcels_Information'
  string featureDatasetName = "Parcels_Information";
  string featureClassName = "Tax_Jurisdiction";

  // Create a FeatureClass description
  FeatureClassDescription featureClassDescription = new FeatureClassDescription(featureClassName,
    new List<FieldDescription>()
    {
      new FieldDescription("Tax_Id", FieldType.Integer),
      new FieldDescription("Address", FieldType.String)
    },
    new ShapeDescription(GeometryType.Point, SpatialReferences.WGS84));

  FeatureDatasetDefinition featureDatasetDefinition = geodatabase.GetDefinition<FeatureDatasetDefinition>(featureDatasetName);

  SchemaBuilder schemaBuilder = new SchemaBuilder(geodatabase);

  // Create a FeatureClass inside a FeatureDataset using a FeatureDatasetDefinition
  schemaBuilder.Create(new FeatureDatasetDescription(featureDatasetDefinition), featureClassDescription);

  // Build status
  bool buildStatus = schemaBuilder.Build();

  // Build errors
  if (!buildStatus)
  {
    IReadOnlyList<string> errors = schemaBuilder.ErrorMessages;
  }
}

public void AddFieldWithDomainSnippet(Geodatabase geodatabase)
{
  // Adding a field,'PipeType', which uses the coded value domain to the 'Pipes' FeatureClass

  //The FeatureClass to add field
  string featureClassName = "Pipes";

  SchemaBuilder schemaBuilder = new SchemaBuilder(geodatabase);

  // Create a CodedValueDomain description for water pipes
  CodedValueDomainDescription pipeDomainDescription =
    new CodedValueDomainDescription("WaterPipeTypes", FieldType.String,
    new SortedList<object, string> { { "C_1", "Copper" },
      { "S_2", "Steel" } })
    {
      SplitPolicy = SplitPolicy.Duplicate,
      MergePolicy = MergePolicy.DefaultValue
    };

  // Create a coded value domain token
  CodedValueDomainToken codedValueDomainToken = schemaBuilder.Create(pipeDomainDescription);

  // Create a new description from domain token
  CodedValueDomainDescription codedValueDomainDescription = new CodedValueDomainDescription(codedValueDomainToken);

  // Create a field named as 'PipeType' using a domain description
  FieldDescription domainFieldDescription = new FieldDescription("PipeType", FieldType.String)
  { DomainDescription = codedValueDomainDescription };

  //Retrieve existing information for 'Pipes' FeatureClass
  FeatureClassDefinition originalFeatureClassDefinition = geodatabase.GetDefinition<FeatureClassDefinition>(featureClassName);
  FeatureClassDescription originalFeatureClassDescription =
    new FeatureClassDescription(originalFeatureClassDefinition);

  // Add domain field on existing fields
  List<FieldDescription> modifiedFieldDescriptions = new List<FieldDescription>(originalFeatureClassDescription.FieldDescriptions) { domainFieldDescription };

  // Create a new description with updated fields for 'Pipes' FeatureClass 
  FeatureClassDescription featureClassDescription =
    new FeatureClassDescription(originalFeatureClassDescription.Name, modifiedFieldDescriptions,
                                   originalFeatureClassDescription.ShapeDescription);

  // Update the 'Pipes' FeatureClass with domain field
  schemaBuilder.Modify(featureClassDescription);

  // Build status
  bool buildStatus = schemaBuilder.Build();

  // Build errors
  if (!buildStatus)
  {
    IReadOnlyList<string> errors = schemaBuilder.ErrorMessages;
  }
}